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排序方式: 共有496条查询结果,搜索用时 15 毫秒
1.
Selenium (Se) toxicity is known to be affected by level of intake of the mineral, but there are conflicting reports on the relative toxicities of the various chemical forms of Se. We monitored Se toxicity in rats fed Torula yeast-based diets containing 0.1, 0.5 or 2.5 micrograms Se/g of diet as either sodium selenate (Na2SeO4) or L-selenomethionine (SeMet). Half the diets were supplemented to contain adequate dietary methionine (Met). Weights were monitored weekly for 6 (Met-adequate) or 7 (Met-deficient) wk, at which time the rats were killed. There were no significant differences in final weight among Met-adequate rats, regardless of level or form of dietary Se. Methionine-deficient rats all gained significantly less weight than their Met-adequate counterparts. Selenosis was most severe in the Met-deficient rats fed 2.5 micrograms Se/g of diet as Na2SeO4, as indicated by significantly impaired weight gains. Nonetheless, Se retention in serum, heart, brain, bone, testes, colon, skin, lungs and pancreas was greater in rats fed SeMet than in those fed Na2SeO4, and Met deficiency further intensified this trend. The kidney was the only organ in which Se levels were markedly higher in the severely poisoned Met-deficient rats fed Na2SeO4. Further research is needed to determine whether elevated kidney Se levels are related to the greater toxicity observed in the Met-deficient rats fed Na2SeO4. 相似文献
2.
Block G Mangels AR Patterson BH Levander OA Norkus EP Taylor PR 《Journal of the American College of Nutrition》1999,18(6):628-637
PURPOSE: To evaluate the role of factors that may affect the level of plasma ascorbic acid (AA), including age, body weight, physical activity, minor illness and the impact of prior depletion and repletion. METHODS: After one month of stabilization on 60 mg vitamin C/day, subjects underwent two complete depletion-repletion cycles (one cycle=one month of vitamin C depletion with nine mg/day, followed by one month of repletion with 117 mg per day). Subjects (68 men, ages 30 to 59 years) did not smoke or drink alcohol during the study. All food was provided by the study. RESULTS: There was extreme individual variability in the plasma AA level achieved on an identical repletion dose: after four weeks at 117 mg/day of vitamin C, AA ranged from 26.8 micromol/L to 85.8 micromol/L. Body weight was inversely associated with plasma AA attained (p<0.0001). Regression analysis indicated that, compared to a 130-lb man, a 200-lb man reached 10 micromol/L lower AA after the first repletion and 18 micromol/L lower AA after the second repletion. One-third of the subjects did not reach a plasma plateau after the first repletion. Prior depletion and apparent repletion also had a major impact, and only 10% of subjects reached the same plasma AA on the second repletion as on the first repletion. CONCLUSIONS: Plasma AA attained on a given dose depends on body weight (or dose per kg of body weight) and on whether or not any prior depletions had been repleted adequately. The results have implications for nutrition recommendations and research design. 相似文献
3.
Demetrius Albanes Arline D. Salbe Orville A. Levander Philip R. Taylor Daniel W. Nixon Myron Winick 《Nutrition and cancer》2013,65(1-2):73-80
Although the inhibitory effect of caloric restriction on tumorigenesis is substantial and well known, the pertinent mechanisms remain to be determined. We recently suggested that the risk of cancer may be directly related to the total number of dividing cells within an affected organ. This study evaluates the effects of early caloric restriction on the cellular growth of the colon. The experiment began one day postpartum and ended six weeks later with the killing of all animals. It consisted of two consecutive periods: a) three weeks of suckling and b) three weeks postweaning. Animals whose food was restricted only during the suckling period showed normal colons when killed at six weeks. Caloric restriction (40%) for three weeks postweaning resulted in colons of lower weight with fewer cells (less total DNA) and reduced total DNA synthesis ([3H]thymidine uptake, dpm/colon) when compared with animals fed ad libitum postweaning. Conversely, only rats fed ad libitum from birth through the first three weeks after weaning demonstrated an increase (21%) in the rate of DNA synthesis (dpm/mg DNA) compared with other animals. In addition, the colonic crypts showed no differences in the number of cells or the number of dividing cells, as determined by autoradiography. By contrast, the total number of crypts (and/or the number of mucosal cells between crypts) are reduced, and hence the total number of colonic mucosal cells dividing at any given time are similarly decreased. The reduced number of dividing cells in the colons of these animals (i.e., those restricted postweaning) could explain previous data suggesting that they are resistant to the induction of colon cancer. 相似文献
4.
Lapidus LJ Ponzer S Elvin A Levander C Lärfars G Rosfors S de Bri E 《Acta orthopaedica》2007,78(4):528-535
Background Skeletal trauma and immobilization are well-known risk factors for deep vein thrombosis (DVT) and pulmonary embolism (PE). While prophylaxis against thromboembolic complications has become routine after major orthopedic surgery, whether or not prophylaxis after minor surgery and lower limb immobilization is necessary is still under debate.
Methods In a double-blind, placebo-controlled study, 272 consecutive patients were randomized to receive either thromboprophylaxis with Dalteparin (n = 136) or placebo (n = 136) for 5 weeks after ankle fracture surgery. All patients received 1 week of initial treatment with Dalteparin before randomization. A unilateral phlebography was performed when the cast was removed.
Results The overall incidence of DVT was 21% (95% CI: 13-29%) in the Dalteparin group and 28% (CI: 19- 37%) in the placebo group (risk ratio = 0.8, CI: 0.6-1.1; p = 0.3). The incidence of proximal DVTs was 4% and 3%, respectively. No major bleeding occurred.
Interpretation We found no significant difference in the incidence of DVT between the 2 treatment groups and our results do not support prolonged thromboprophylaxis. The overall incidence of DVT was high, reflecting the potential risk of PE and post-thrombotic syndrome after ankle fracture surgery. Most of the DVTs were asymptomatic, however, and were located in distal veins. 相似文献
Methods In a double-blind, placebo-controlled study, 272 consecutive patients were randomized to receive either thromboprophylaxis with Dalteparin (n = 136) or placebo (n = 136) for 5 weeks after ankle fracture surgery. All patients received 1 week of initial treatment with Dalteparin before randomization. A unilateral phlebography was performed when the cast was removed.
Results The overall incidence of DVT was 21% (95% CI: 13-29%) in the Dalteparin group and 28% (CI: 19- 37%) in the placebo group (risk ratio = 0.8, CI: 0.6-1.1; p = 0.3). The incidence of proximal DVTs was 4% and 3%, respectively. No major bleeding occurred.
Interpretation We found no significant difference in the incidence of DVT between the 2 treatment groups and our results do not support prolonged thromboprophylaxis. The overall incidence of DVT was high, reflecting the potential risk of PE and post-thrombotic syndrome after ankle fracture surgery. Most of the DVTs were asymptomatic, however, and were located in distal veins. 相似文献
5.
Zusammenfassung In dieser Arbeit wurden die Gebisse von 31 männlichen und 45 weiblichen Dysgnathieträgern mit Hilfe des Berliner Meßsystems vermessen und die Ergebnisse mit Hilfe eines Computers ausgewertet. Es erfolgt der Vergleich der Parameter zwischen Probanden mit Progenie, Kreuzbiß, offenem Biß und Schmalkiefer. Die Veränderung der Werte wurden longitudinal in den Hauptentwicklungsstufen Milchgebiß, Wechselgebiß und im bleibenden Gebiß untersucht. Dabei werden auch nach der Behandlung noch zwischen den Anomaliegruppen bei einzelnen Werten signifikante Unterschiede gefunden.
Summary In this study dental plaster casts of 31 male and 45 female subjects were measured using the Berlin measurement system and evaluated with the aid of a computer. The parameters of subjects with class III malocclusion, crossbite, open bite and class II/1 malocclusion were compared. The changes were studied longitudinally in the main developmental stages, namely the deciduous, mixed and permanent dentitions. Significant differences were found also following treatment between the malocclusion groups.
Résumé On a mesuré les dentures de 31 hommes et 45 femmes présentant des dysgnathies à l'aide du système de mesure mis au point à Berlin; les valeurs ainsi établies on fait l'objet d'un traitement sur ordinateur. On a procédé à la comparaison des paramètres des sujets atteints de prognathie inférieure, occlusion croisée, béance et endognathie. On a étudié la modification des valeurs de manière longitudinale, en suivant les principales étapes d'évolution: denture lactéale, denture mixte et denture permanente. L'examen a permis, même après le traitement, d'établir, pour chacune des valeurs, des différences importantes d'un groupe d'anomalie à l'autre.相似文献
6.
Summary Right brain-damaged patients with left spatial neglect were examined on a tactile maze task. They started to explore the right side of the maze and their search times were longer on the left side. Their performance was the same whether blindfolded or not, which contrasts with the results of other studies and probably reflects differences in task demand. The present results do not support a previous observation that visual neglect can be compensated through the tactile modality. Our patients had markedly longer search times than normal controls in the right as well as the left hemifield, and search times in both hemifields were positively correlated. The outcome of the maze test in this context may therefore depend to a large extent on impaired topo graphical processing. 相似文献
7.
The therapeutic results of operatively and conservatively treated patients with lumbar disc syndromes were reviewed in a retrospective study. The patients were treated during a 10-years period (1976-1985). A total of 330 patients with lumbar disc prolapses were treated in the hospital during this period 44% were treated surgically. The data on 100 operated and 100 conservatively treated cases, registered in this random test sample, have been compared with respect to: pain; neurological deficits; subjective problems and sociomedical questions. The average patient age of both groups was about 41 years, and the patients predominant were male (about 70%). The therapeutic results of both operatively and conservatively treated patients were good, which is also by the high percentage of employment (80%-90%) in the two treatment groups. The critical evaluation showed more neurological disturbances and limited vocational activity in the group of cases operated upon. More than 70% of the operated cases showed radicular syndromes of the follow-up examination although it was not of essential functional importance. The period inability to work and the percentage of disablement were also much higher in this group. The pain symptoms were particularly relevant in our examination. Only 12%-16% of the patients in the two groups that took part in the follow-up examinations reported freedom from pain. It was apparent that atypical pain syndromes were correlated with personality psychological disturbances. Nearly one-third of our patients mentioned psychological problems. The prognosis of the conservative treatment of lumbar disc prolapse was equivalent to operative therapy (disregarding the absolute indications for operations). There were no definite advantages found for either of the two methods of treatment. The necessity for a specialized follow-up treatment of patients with sciatica due to herniated lumbar discs is discussed, and differentiated selection for operative therapy is given. Here the treatment of pain should be considered most important. 相似文献
8.
OA Adaramoye 《African health sciences》2012,12(4):498-506
Background
Hypoglycaemic effect of kolaviron (KV), (biflavonoid from Garcinia kola) in streptozotocin (STZ)-diabetic rats has been established.Objectives
To evaluate the possible protective effects of KV on cardiac, renal and hepatic tissues of STZ-diabetic rats.Methods
This study consists of four groups of 6 rats each. Groups one and two contained non-diabetic and untreated-diabetic rats, respectively. Groups three and four were made up of KV- and glibenclamide (GB) - treated diabetic rats, respectively.Results
STZ-intoxication caused a significant (p<0.05) increase in the relative weight of liver in diabetic rats. STZ-diabetic rats had significant increase (p<0.05) in the levels of fasting blood glucose (FBG), á-amylase and HbA1c. A marked and significant (p<0.05) increase in the levels of cardiac, renal and liver marker indices such as serum creatine kinase, lactate dehydrogenase, creatinine, urea and alanine aminotransferase were observed in untreated diabetic rats. Also, untreated diabetic rats had significantly (p<0.05) elevated urinary glucose and protein and, lowered creatinine clearance. In KV- and GB- treated groups, the levels of FBG, á-amylase and HbA1c were significantly (p<0.05) reduced, while treatment with KV significantly (p<0.05) attenuated the cardiac, renal and liver marker indices.Conclusion
KV offered significant antidiabetic and tissues protective effects in the rats. 相似文献9.
Mutational analysis of the SOX9 gene in campomelic dysplasia and autosomal sex reversal: lack of genotype/phenotype correlations 总被引:9,自引:1,他引:9
Meyer J; Sudbeck P; Held M; Wagner T; Schmitz ML; Bricarelli FD; Eggermont E; Friedrich U; Haas OA; Kobelt A; Leroy JG; Van Maldergem L; Michel E; Mitulla B; Pfeiffer RA; Schinzel A; Schmidt H; Scherer G 《Human molecular genetics》1997,6(1):91-98
It has previously been shown that, in the heterozygous state, mutations in
the SOX9 gene cause campomelic dysplasia (CD) and the often associated
autosomal XY sex reversal. In 12 CD patients, 10 novel mutations and one
recurrent mutation were characterized in one SOX9 allele each, and in one
case, no mutation was found. Four missense mutations are all located within
the high mobility group (HMG) domain. They either reduce or abolish the
DNA-binding ability of the mutant SOX9 proteins. Among the five nonsense
and three frameshift mutations identified, two leave the C-terminal
transactivation (TA) domain encompassing residues 402-509 of SOX9 partly or
almost completely intact. When tested in cell transfection experiments, the
recurrent nonsense mutation Y440X, found in two patients who survived for
four and more than 9 years, respectively, exhibits some residual
transactivation ability. In contrast, a frameshift mutation extending the
protein by 70 residues at codon 507, found in a patient who died shortly
after birth, showed no transactivation. This is apparently due to
instability of the mutant SOX9 protein as demonstrated by Western blotting.
Amino acid substitutions and nonsense mutations are found in patients with
and without XY sex reversal, indicating that sex reversal in CD is subject
to variable penetrance. Finally, none of 18 female patients with XY gonadal
dysgenesis (Swyer syndrome) showed an altered SOX9 banding pattern in SSCP
assays, providing evidence that SOX9 mutations do not usually result in XY
sex reversal without skeletal malformations.
相似文献
10.
Mats Fredrikson Gunnar Edman Sten E. Levander Daisy Schalling Jan Svensson Martti Tuomisto 《Psychophysiology》1990,27(6):649-655
Electrodermal responses were recorded during the presentation of 16 moderately intense (1000 Hz, 90dB) tones in three groups of young men: borderline hypertensives (138/79 mmHg), normotensives (112/65 mmHg), and hypotensives (104/63 mmHg). Electrodermal response habituation was measured as a decline in response over trials, number of trials to a response criterion of three successive nonresponses, and number of inversions of response amplitude (larger responses following smaller responses) in the stimulus sequence. Habituation was fastest in hypotensives. Nonspecific electrodermal responses at rest and during tone presentations were most frequent in borderline hypertensives, least frequent in the hypotensive group, with the normotensive group falling in between. There were no significant differences in electrodermal level. The rapid habituation rate in hypotensives is discussed in terms of cursory information processing associated with impulsive behaviour. The higher nonspecific electrodermal activity in borderline hypertensives is interpreted to indicate increased sympathetic nervous system activity. 相似文献